1. Field of the Invention
The present invention relates generally to the field of valves for controlling the flow of fluid through a control opening, and more particularly to an improved valve having a cantilevered piezoelectric bar, the free end of which is arranged to be selectively moved toward and away from a control opening.
2. Description of the Prior Art
Many types of valves are, of course, known. These valves generally contemplate that a member move toward and away from a valve seat.
A piezoelectric member is, in effect, an electromechanical transducer, in which application of an electrical signal produces a change in a corresponding mechanical parameter, and vice versa. Piezoelectric elements have found usage in a number of different applications, such as oscillators, switches, relays and pressure regulators. Examples of such uses are shown in U.S. Pat. Nos. 2,928,409; 3,683,212; 4,093,883; and 2,166,763.
Heretofore, diabetics would receive a large initial dose of insulin, via injection or oral medication, at one time. Recently, however, it has been proposed to implant a device in the body which would supply smaller doses of such medication at regular intervals. Examples of such implantable devices are described in U.S. Pat. No. 4,077,405, and in an article, Blackshear, Rohde, Varco and Buchwald, One Year of Continuous Heparinization in the Dog Using a Totally Implantable Infusion Pump, Surgery, Gynecology & Obstetrics, August, 1975, Vol. 141, pp. 176-186.